Orthodontic brackets typically are attached to individual teeth and connected to an archwire so as to apply appropriate force over time to move and straighten teeth. Specifically, teeth are moved and rotated by applying forces to the brackets via the archwire. Periodic visits to the orthodontist are therefore required so that the assembly may be checked and adjusted to ensure the proper amount and direction of force is being applied by the archwire to the teeth via the brackets. Adjustment of the archwire is, however, a highly subjective endeavor. Orthodontists therefore gain practical knowledge of the amount and direction of force that is needed for an individual orthodontic patient.
It would, however, be highly advantageous if the magnitude and direction of force applied to an orthodontic bracket could be determined objectively. It is towards fulfilling such a need that the present invention is directed.
Broadly, the present invention is embodied in a force-responsive orthodontic bracket. More specifically, the orthodontic bracket of the present invention allows for the objective determination of the magnitude and/or direction of force applied to the tooth to which the bracket is attached. The present invention is therefore preferably embodied in orthodontic brackets having an elastomeric member which allows one portion of the bracket to be resiliently moveable relative to at least one other portion of the bracket. The bracket preferably includes an indicator (e.g., fiducial marks) which distort in response to movement of the bracket portions relative to one another, whereby the indicator distortion is indicative of the magnitude and/or direction of a force applied to the bracket.
In especially preferred embodiments, the present invention includes a force-responsive orthodontic bracket having a lower base member, an upper bracket member, and an elastomeric layer interposed between the lower base and upper bracket members. The elastomeric layer therefore comprises an elastomeric member which allows the upper bracket member to be moveable resiliently relative to the lower base member.
The orthodontic brackets of the present invention are advantageously employed as part of a system whereby the bracket includes an indicator for an indicator of force applied to the upper bracket member sufficient to cause resilient movement of the upper bracket member relative to the lower base member. An optical detector may be provided to optically detect the indicator and issue an output signal indicative of the relative resilient movement between the lower base and upper bracket members. A processor receives the output signal from the optical detector to provide an indication of magnitude and/or direction of the force applied to the upper bracket member.
These and other aspects and advantages will become more apparent after careful consideration is given to the following detailed description of the preferred exemplary embodiments thereof.